Tall, moody, strong and very brave, Dwalin is a Dwarf through and through. A famous warrior, powerful ally and muscular, Dwalin would like nothing more than to see the return of the Dwarven King under the Mountain.

Later in TA 2841, Dwalin, along with his brother Balin, and a few others accompanied Thráin when he left the Ered Luin to visit Erebor. The small party was dogged by the emissaries of Sauron. In TA 2845, Thráin was captured one night when he and his companions sheltered under the eaves of Mirkwood from a black rain. After a fruitless search for their leader, the Dwarves gave up and returned to Thorin to inform him the news.

Dwalin was the first Dwarf to arrive, alone, at Bag End when the unexpected party began at Bilbo's hobbit hole. He was wearing a dark-green hood and walked in as if expected, which greatly surprised Bilbo. Soon Balin arrived and he and Dwalin sat talking while Bilbo kept answering the door for the arrival of more and more Dwarves. Later, when Bilbo griped aloud in his kitchen about the lack of help in setting out refreshments, Dwalin and Balin were the first (followed by Fíli and Kíli) to lend a hand. Later still, when the Dwarves filled Bag End with music, Dwalin played on a viol as big as himself.[1] Dwalin lent a green hood and cloak to Bilbo when they set out on their journey.

After reclaiming the mountain from Smaug, Dwalin fought in the Battle of Five Armies and was one of those that survived the terrible battle. He later received his fourteenth share and chose to live in Erebor under the rule of Dáin II Ironfoot, Thorin's cousin.

Dwalin was one of seven of the ten Dwarves of Thorin's company who were still living in Erebor when Frodo came to Rivendell, as reported by Glóin. After the War of the Ring was over, resulting the defeat of Sauron and the destruction of the One Ring, Dwalin lived throughout his life in the Fourth Age in Middle-earth and passed away in FO 91 at the age of 340, considered later than any other known date of death for others of the company.[2][3]

In Peter Jackson's live-action adaptation, he was portrayed by Scottish actor Graham McTavish. The studio released the following statement regarding Dwalin in the trilogy:

Dwalin in the pantry at Bag End

Renowned as a great Warrior, Dwalin speaks his mind plainly and is not one to suffer fools lightly. Fiercely loyal, he was Thorin Oakenshield's staunchest supporter with an unshakeable belief in his friend's leadership. A powerful and bruising fighter, Dwalin has a natural tendency to distrust anyone who is not a Dwarf and is particularly suspicious of Elves. Proud, brave and one of the tallest of the Dwarves, Dwalin will bow to none but those who have earned his respect.

During the events of The Hobbit: The Desolation of Smaug, Dwalin has his weapons stripped from him after being captured by the wood elves of Mirkwood. Following the company's escape and their encounter with Bard the Bowman, Dwalin openly voices his mistrust of Bard; suggesting that they throw him overboard and take his boat by force. He later equips himself with a large two-handed mace from Lake Town's armory for the raid on the Lonely Mountain. (The Hobbit: The Desolation of Smaug (2013))

In The Hobbit: The Battle of the Five Armies, Dwalin along with the other dwarves follow Thorin as they barricade themselves inside Erebor. After Dain's army arrives and begins to fight Azog's huge orc army, Thorin refuses to aid his cousin. Dwalin tries to persuade Thorin to aid them, saying that Thorin is less of a man than he has even been. Dwalin then follows Thorin, Fili and Kili to Ravenhill to fight Azog. He witnesses Fili's death, and later comes to Bilbo's aid and fights off the orcs. Dwalin then bows to Thorin's body after the battle. He is last seen with the rest of the company saying goodbye to Bilbo. (The Hobbit: The Battle of the Five Armies(2014)).

In The Lord of the Rings Online, after Thorin's death, Gormr Doursmith took over Thorin's Halls' leadership but with his consequent defeat at the hands of Dwalin, Dwalin became Lord of the Longbeards in the Blue Mountains and Steward of Thorin's Halls. Before the War of the Ring, he led an expedition to Dourhands' territory, south of the city. Some members of his party fell ill to a strange disease, but were cured later by a fellow Longbeard who had discovered a cure at Dwalin's request. Eventually he discovered the source and stopped it, however he failed to prevent the resurrection of Skorgrim, the ancient King of the Dourhands. Under his leadership, the Longbeards recovered the region from the Dourhands. Dwalin says that he tries to rule the Halls as well as Thorin would in his tribute. He claims he hasn't seen his brother Balin for a while and also that he misses the Lonely Mountain. In LEGO The Hobbit: The Video Game, he can use his hammer to push large Legos.

Contrary to popular fandom belief, nothing about Dwalin's life post-BOFA is cited in any of Tolkien's works. Whether or not he had children is merely speculation, as none are listed for him in Gimli's genealogy.

Each of the Hobbit film's actors had a voice in the nature and design of their own weaponry. Graham McTavish, who plays Dwalin, named the dwarf's twin battle axes Grasper and Keeper because when they were first shooting tests for Dwalin, Graham McTavish said "This one Grasps your soul, this one keeps it" about his Dwarven axes.